Mixer buckets are usually tools that, coupled to the ends of the arms of an excavator, allow to produce concrete after having taken sand from a deposit, having positioned the bucket with the mouth thereof facing upwards, so that it can be assimilated to a hopper, having inserted inside it cement and water, and any other ingredients necessary to obtain a concrete of given composition, and having mixed all the ingredients by means of an Archimedes' screw contained inside the bucket.
Usually, the bottom of the bucket has an opening for concrete discharge, arranged centrally, and is suitable to couple with a funnel-shaped member that, in turn, carries a discharging channel. Obviously, to perform this operation the bucket shall be raised and maintained in a position of maximal height so as to allow an operator to position the funnel-shaped member below it, i.e. to connect the funnel-shaped member to the bucket, in correspondence of the opening. This operation is particularly dangerous due to the instability of the bucket in this position, often resulting in discharging the concrete onto the operator, with sometimes fatal consequences. To avoid these terrible consequences, it has been thought to provide the opening in lateral position, in correspondence of a flank of the bucket, so as to allow an operator to stay outside the bucket's projection onto the ground, and therefore to be not subjected to any consequences in case of overturning of the bucket filled with concrete. However, providing the discharge opening of the bucket laterally, within the projection and near one of the flanks causes a not negligible inconvenience; in fact, the concrete supplied by means of the Archimedes' screw towards the lateral portion of the bucket becomes compact and loses fluidity, and it is therefore more difficult to discharge it. To avoid this inconvenience, it is necessary to activate the Archimedes' screw in opposite rotational directions, thus slowing down the times necessary for discharging.
In view of the situation described above, it would be desirable to have available a mixer bucket that, in addition to limiting and possibly overcoming the drawbacks of the prior art, defines a new standard for this kind of tools, both as regards the product and the mode of use, i.e. the method performed to mix safely the ingredients, without risks for the operator and without the need for performing operations in order to make the concrete contained inside the bucket less compact.